11-cmake语法-函数和宏的定义

时间 2019-11-20

标签 cmake 语法函数定义繁體版

原文原文链接

cmake语法不单单能够适用于 CMakeLists.txt，也适用于 xxx.cmake 文档。bash

在 OpenCV 的 CMakeLists.txt 中，不少 ocv_XXX() 的函数，都是定义在相应的 xxx.cmake 中。函数

好比：L116blog

include(cmake/OpenCVUtils.cmake)

# must go before the project command

# @ 解说：
# @ ocv_update 函数定义在 cmake/OpenCVUtils.cmake 这个组件中，能够用Notepad++打开看看。
ocv_update(CMAKE_CONFIGURATION_TYPES "Debug;Release" CACHE STRING "Configs" FORCE)
if(DEFINED CMAKE_BUILD_TYPE)
  set_property( CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS ${CMAKE_CONFIGURATION_TYPES} )
endif()

函数定义：

function(函数名 参数名)

  ...

endfunction()

例子：cmake/OpenCVMinDepVersions.cmake中文档

function(ocv_cmake_eval var_name)
  if(DEFINED ${var_name})
    file(WRITE "${CMAKE_BINARY_DIR}/CMakeCommand-${var_name}.cmake" ${${var_name}})
    include("${CMAKE_BINARY_DIR}/CMakeCommand-${var_name}.cmake")
  endif()
  if(";${ARGN};" MATCHES ";ONCE;")
    unset(${var_name} CACHE)
  endif()
endfunction()

宏的定义：

macro(宏名 参数)
  ...
endmacro()

例子：cmake/OpenCVMinDepVersions.cmake中io

macro(ocv_cmake_configure file_name var_name)
  configure_file(${file_name} "${CMAKE_BINARY_DIR}/CMakeConfig-${var_name}.cmake" ${ARGN})
  file(READ "${CMAKE_BINARY_DIR}/CMakeConfig-${var_name}.cmake" ${var_name})
endmacro()

函数和宏不支持return，须要传参出去，能够经过形参输入传出。function

macro(ocv_xxx return_hello_world)
  set(return_hello_world "Hello_World")
endmacro()

参考：class

https://www.jianshu.com/p/44ba033c262adate